Space-fed antenna arrays are currently used in radar and communications applications. They enjoy particular advantage over other antenna types (corporate-fed arrays or reflector systems) when requirements demand very large aperture size. In fact, this class of antenna may assume lengths of over two hundred feet when deployed for space usage. They can be rolled in "window-shade" fashion while stowed, for transportation into orbit or during storage on Earth, and then can be unrolled when needed as a radiating device.
Usually, when these space-fed lens antennas are designed for a space mission, they must be extremely light to permit their efficient transport from Earth to orbit altitudes. In addition, their construction will not permit a total unrolling and deployment under the influence of the Earth's gravitational force. The array would become seriously deformed, and unless it were supported might destroy itself. Herein resides the motivation for this invention. Since the array cannot be fully opened on Earth, how can it be tested before an expensive launch into orbit? Conventional far-field, near-field, and focused near-field testing approaches all require a fully opened antenna to test. This invention, on the other hand, tests one "exposed" portion of the array at a time, as the array is unrolled from one "window-shade" canister onto another "window-shade" canister.